“Since their reintroduction into Yellowstone National Park, gray wolves have migrated to western states (including agricultural lands in Idaho and Oregon) and hunted in livestock grazing areas.

Producers reported losing animals to wolf-related injury and death. And, on top of that, they said cows that witnessed wolf attacks exhibited nervous, aggressive and excitable behavior toward humans and dogs. Producers said these cows also had lower pregnancy rates, were more sickly, and their calves weighed less.

Cooke hypothesized that these reported responses can be associated with the stress that cows experienced when they graze lands where wolves are present. He added that merely sensing (seeing, smelling or hearing) a predator can elicit these stress responses. And multiple studies by Cooke and other researchers had already established a link between cow stress and decreases in their productivity and welfare.”<<<Read More>>>